NONSPECIFIC ESTERASES IN RAT PROSTATIC EPITHELIAL CELLS

Abstract

Prostates from normal and recently castrated rats were examined for the localization of esterase activity using Holt's indoxyl acetate method. Tissue fixed in formalin mixtures containing sucrose showed preservation of abundant cytoplasmic esterase activity while tissue fixed in formalin mixtures lacking sucrose had little cytoplasmic esterase activity. Esterase activity in droplets was abundant after both fixations. The difference could not be explained by ferroferricyanide inhibition, pH or osmolality of the fixative, and is attributed to a protective effect of sucrose during fixation. E600 greatly reduced cytoplasmic esterase activity in normal and castrated rats. Esterase activity in droplets was resistant to E600 in both normals and castrates. Ribonuclease extraction reduced cytoplasmic esterase activity in both normal and castrated rats only slightly, indicating no association of cytoplasmic esterases with ribosomal ribonucleic acid. Cytoplasmic esterase activity is reduced in castrates in which the epithelial cells of the prostate also show a decrease in endoplasmic reticulum and ribosomes. Similarity of location of droplet esterase activity and of lysosomes marked by acid phosphatase and reduction in droplet esterase activity by saline extraction are cited as evidence for a lysosomal localization of E600-resistant esterase.